CFB oxyfuel technology experimental and theoretical research
|Keywords||CFB Oxyfuel O2/CO2 atmosphere Flue gas recirculation CHAR Thermobalance Thermodynamic analysis Calcination Vulcanization Pore ??structure Limestone Circulating fluidized bed multi-functional integrated test bed Combustion efficiency Simulation|
Global warming, the greenhouse effect is due to the CO 2 to represent significant emissions of greenhouse gases caused by the intensification of the greenhouse effect caused. In various greenhouse gases, CO 2 with its longer life spans and high emissions while the \CO 2 primarily from fossil fuel combustion process, with the rapid social and economic development brought about by the growing demand for energy, the use of fossil fuel combustion also growing, this has led to CO 2 emissions are increasing. In reducing CO 2 emissions impact of the strategy, nothing more than controlling CO 2 generation and recycling CO 2 two kinds policies. By adjusting energy structure, improving power generation efficiency, promote energy efficiency and development of renewable energy and new energy and other measures to control CO 2 a lot of emissions. CO 2 can be recovered from the combustion exhaust gas into the separation process and separated from the atmosphere, both fixed. Currently, to take capture, storage and utilization of fossil fuel combustion CO 2 method is considered to be in the near future mitigation CO 2 emissions more feasible measures and technologies. Separated from the boiler flue gas CO 2 to a certain extent, so that plant efficiency, power generation costs, mainly coal-fired boiler flue gas in CO 2 concentration typically only 3 to 15% in the lower pressure with nitrogen as the main component from a mixed gas separating a lower concentration of CO 2 Gas is very difficult, resulting in separation of complex equipment, higher cost. If you can greatly improve the combustion process in the combustion products of CO 2 concentration, will make CO 2 separation and recovery costs. Tissue oxygen and carbon dioxide in the fuel gas mixture called oxyfuel combustion technology is in this context that the initiative. Oxyfuel technology is also known as O 2 / CO 2 combustion technology, or an air separation / flue gas recirculation technology. Oxyfuel technology not only enables separation collect CO 2 and processing SO 2 is easy to carry, but also to reduce NOx emissions, is a way to integrated control emissions of coal-fired new clean combustion technology. Oxyfuel technology in thermal power plant variety CO 2 emissions control method is better technical and economic, the application potential. Circulating fluidized bed combustion technology will be enriched and oxygen circulating fluidized bed combustion technology combines the advantages, it is possible to obtain better results. In this thesis, thermal balance, a small desk and a circulating fluidized bed pilot multi-functional test bench three test device. In the heat balance on the O 2 / N 2 atmosphere with O 2 / CO 2 atmosphere of coal pyrolysis, ignition and burning embers and limestone calcination reaction kinetics characteristics; trial bench in a small fluidized bed of limestone in O 2 / CO 2 atmosphere of calcination reaction with the curing characteristics; in the design, build multi-functional integrated CFB test rig O 2 / N 2 atmosphere with O 2 < / sub> / CO 2 atmosphere of coal combustion characteristics and regularity of pollutant emissions. Using thermobalance (TGA) of the two coal particles and two kinds of limestone particles respectively O 2 / CO 2 atmosphere, O 2 / N 2 atmosphere response characteristics were studied, obtained in the area of ??chemical kinetics control coal and limestone kinetic parameters, as well as O 2 and CO 2 (N 2 ) changes in the relationship between the proportion of coal and limestone TGA reaction, and by theoretical analysis of the test results were simulated. Thermodynamics and small fluidized bed test rig study of air and O 2 / CO 2 atmosphere limestone calcination and curing reaction characteristics, and the calcination process and vulcanization limestone samples during the reaction combined pressure mercury analyzer and scanning electron microscope and microscopic analysis, obtained O 2 / CO 2 atmosphere limestone calcination reaction with sulfide Special Zhejiang University PhD thesis point to explore the 02/CO: atmosphere limestone vulcanization reaction mechanism. Design and build a circulating fluidized bed multi-functional integrated test stand and electrical control and monitoring system for Oz / CO: atmosphere and the 02 plus 2 atmosphere coal combustion characteristics and pollutant emissions for a multi-state law test, got in Oz / CO: and 02 destroyers 2 ratio between operating conditions such as changes in the circulating fluidized bed coal combustion characteristics and pollutant emissions laws. Zhejiang University for many years in experimental and theoretical study of CFB achieved in the field of research results based on the combination oxyfuel flue gas recirculation, coking reactions, 50: and NO; generated reactive atmosphere and other aspects of physical properties unique, considering the hydrodynamic characteristics of circulating fluidized bed, coal combustion and gas phase reactions, 50: Emissions and NO, generating degradation rule, the heat transfer characteristics and the separation efficiency, etc., in the mass balance and energy balance based on the established a circulating fluidized bed combustion model enriched. Simulation results and experimental results were compared test bench, while oxygen from circulating fluidized bed combustion technology application point of view, the use of this model for a steel company, Zhejiang University Design 75 than circulating fluidized bed boiler was simulated and prediction, to obtain industrial circulating fluidized bed boiler oxyfuel technology-related features, combined with experimental results and model predictions CFB summed up the advantages of oxyfuel technology and current pilot oxyfuel technology research and application areas there are several major issues are described, as CFB oxyfuel technology to do the practical industrial application of the necessary preliminary experimental and theoretical preparation.